<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>折角效果</title>
    <style>
        .box{
            width: 200px;
            height: 100px;
            font-size: 40px;
            line-height: 100px;
            color: #fff;
            text-align: center;
            /* 线性渐变 */
            background: linear-gradient(to left bottom, transparent 50%, #333 0) 
            no-repeat 100% 0 / 30px 30px,
                linear-gradient(225deg, transparent 20px, #ccc 0)
            ;
        }
    </style>
</head>
<body>
    <div class="box">
        Tag
    </div>
</body>
</html>